NEW BRITISH ANNELIDS. 263 



segments. I found as many as four seta in two of the bundles, and, 

 according to the accepted theory respecting this genus, the setce 

 should always be in even numbers (2, 4, 6, 8) ,- but the rule is by no 

 means invariable. In one specimen the four posterior segments 

 ivere without setce, and the penultimate set of four had only one 

 seta in each sac. A marked peculiarity of this species is to be 

 found in the colour of the blood, which is decidedly disposed to be 

 red, as may be seen when the worm has been kept for a day or two 

 in clean ivater. The body segments are striate, with about half a 

 dozen rows of striate cells per segment. The girdle extends over 

 segment xii and the hinder half of segment xi, the usual gland- 

 pores being found on the former segment. I traced the dorsal 

 blood-vessel to segment xviii, so it is post-clitellian in origin. The 

 egg-sac extended back to the sixteenth segment. The blood-vessels 

 in segments i-iv did not differ greatly in arrangements from that 

 ivhich usually prevails, the dorsal vessel giving off tiuo branches on 

 each side in the third segment, ivhich formed loops and joined the 

 returning vessels caused by the dorsal vessel dividing into two at 

 the head. I found heart-like swellings in segments vii, viii, ix. 

 The brain is nearly as broad as long, convex behind, and very 

 slightly concave in front, the outline being slightly oval rather than 

 circular. The coiled tube of segment xi is very long and fine ; but 

 the most obvious characteristic is found in the spermathecce. There 

 is a pair of sacs at the base of the pouch which is attached to the 

 intestine, and at the outer extremity, between segments iv and v, the 

 aperture of the spermathecal tube has a pair of large brown glands. 

 These are so conspicuous that when first seen they have all the 

 appearance of eye-spots. The length of the tube is about three 

 times the width of the sacs. 



I have named the species magna, because it is by far the 

 largest yet described. I have not studied the nephridia, nor 

 have I as yet determined the salivary glands, for want of material. 

 The worm, which is sluggish in its habits, is found in moist 

 places by slowly moving water. I found the same worm, or a 

 close ally, at Hastings last summer, but, as only one specimen 

 was taken, and one's holiday equipment does not render identi- 

 cations easy, the exact species was not determined, 



